As the video details, it's not terribly complicated, as long as you know where to find a spigot and a giant pumpkin. You basically prep as you would for pumpkin carving, and then just dump all your beer into it. We have our suspicions that this might make your beer taste oddly like raw pumpkin, but there's really only one way to find out.
Also... we're going to guess that roasting your beer-soaked pumpkin after it's finished its duty as a keg would probably not be the worst thing.
[via Laughing Squid]